Forced air cooling and ventilating system for self-cleaning oven



y 1968 K. E. RAWALD ETAL 3,3 7

FORCED AIR COOLING AND VENTILATING SYSTEM FOR SELF'CLEANING OVEN Filed July 25, 1966 Maw/e 65 7 POM/6? f r ca/vmoz 55 6 COM/790A IA VEAITOES. KfA/NfTH f. ZA WALD Calif/57M E. 506?.5/

d-ZMZQQQQM 4 Tram/5y United States Patent 3,384,067 FORCED AIR COOLING AND VENTILATING SYSTEM FOR SELF-CLEANING OVEN Kenneth E. Rawald, Anaheim, and Christian E.

Buerki, Fullerton, Calif., assignors to Norris- Thermador Corporation, Los Angeles, Calif, a corporation of California Filed July 25, 1966, Ser. No. 567,677 1 Claim. (Cl. 126-21) ABSTRACT OF THE DISCLOSURE An air jacket is provided between an oven shell and a housing surrounding such shell. Venting openings are provided in the oven shell to permit exhaust gasses from the oven to pass into the air jacket and mix with cool air from the outside. Fan means interposed between the jacket and exhaust piping draws outside ambient air into the jacket through air intakes in the housing, the oven having a heater control for self-cleaning operation which is interlocked with the fan means so that it can be actuated only when the fan means is operating.

This invention relates to a cooling and ventilating system for a self-cleaning oven and more particularly to such a system which utilizes forced air cooling through an air jacket which surrounds the oven and which is capable of safely venting the exhaust gasses and heated air outdoors.

In a self-cleaning oven, the oven is heated to a very high temperature (of the order of 900 F.) at which temperature the food soil breaks down and disappears in the oven exhaust. With the oven heated to such high temperatures, it is essential that measures be taken to prevent both the exhaust piping and the outer portions of the oven housing from reaching high temperatures which might pose a safety hazard.

In self-cleaning ovens of the prior art, the use of exhaust piping has not been feasible due to the overheating of such piping. In such prior art devices, therefore, the exhaust gasses and the heated air from the forced air cooling system are generally vented into the kitchen with the obvious undesirable effects of such venting.

The device of this invention overcomes the shortcomings of prior art self-cleaning ovens by providing means for air-cooling the areas surrounding the oven and the exhaust gasses thereof sufficiently to enable the utilization of ordinary single walled exhaust piping and to prevent over-heating of the outer housing during the selfcleaning operation.

The device of the invention achieves this desired end result by providing an air jacket between the sides, back, top and bottom portions of the oven and the housing. Fan means is provided which draws outside ambient air into the jacket through air intakes provided between the oven cabinet and the oven housing along the sides and across the bottom portions thereof. Venting openings are also provided in the oven shell to permit exhaust gasses from the oven to pass into specific air jackets where they are mixed with the air drawn in from the outside. Thus a large volume of ambient air is mixed with a comparatively small volume of oven exhaust gasses to effectively cool the exhaust from the oven before it is passed into the exhaust piping. The device of this invention thus provides highly effective means for both venting and cooling an oven to avoid overheating of the exhaust piping and the outer portions of the oven housing during the self-cleaning operation.

It is therefore an object of this invention to provide improved means for ventilating and cooling an oven during its self-cleaning mode of operation.

It is another object of this invention to enable the outdoor exhausting of heated air and exhaust gasses in selfcleaning oven operation.

It is still another object of this invention to provide simple yet highly effective means for preventing the overheating of an oven during the self-cleaning operation thereof.

Other objects of this invention will become apparent from the following description taken in connection with the accompanying drawings, of which FIG. 1 is a perspective view illustrating an oven incorporating a preferred embodiment of the device of the invention,

FIG. 2 is an elevation view in cross section of the embodiment of FIG. 1 and taken along the plane indicated by 2-2 in FIG. 1.

FIG. 3 is a top plan view taken along the plane indicated by 33 in FIG. 2,

FIG. 4 is a block diagram illustrating a blower motor control which may be utilized in the preferred embodiment of the device of the invention, and

FIG. 5 is a block diagram illustrating a self-cleaning heating control mechanism which may be utilized in the preferred embodiment of the device of the invention.

Referring now to FIGS. l3, a preferred embodiment of the device of the invention is illustrated. Oven shell or can 11 which forms the oven compartment is attached to the oven housing 12 by means of brackets 14. Located between oven shell 11 and the housing is container member 16 which is attached to the housing and forms a compartment for holding thermal insulating material 18 around the oven. Oven door assembly 20 provides a closure for the oven shell.

Oven housing 12 has a lip portion 12a formed around the front thereof, which is used to mount the housing in a cabinet 26 which may be constructed to receive the housing. Lip portion 12a is attached to cabinet 26 by means of screws 28. Located between lip portion 12a and cabinet 26 around screws 28 are spacers 30 which may be fabricated of plastic and which separate lip 12a from the cabinet to provide an air space therebetween. Housing 12 has louver members formed on the forward portions of the sides thereof which provide an air path to air jacket 36 and act to separate the sides of housing 12 from cabinet 26 to prevent the air path from being blocked.

Air jacket 36 is formed between the outer walls of container 16 and the inner wall of housing 12 on the top, bottom, rear and side portions thereof. Fan 40 which is rotatably driven by motor 41 is mounted in the top portions of housing 12. Mounted on the front wall of housing 12 are filter members 42 which have front shield members 42a for directing the flow of air as indicated by arrows 45 from the oven shell through the filter. During the self-cleaning operation, with oven door 20 tightly closed, such air flow occurs through venting slits 11a formed in the lip of the oven shell.

The power to motor 41 is controlled through thermostat which senses the oven temperature and provides power to motor 41 from power source (as indicated in FIG. 4) whenever the oven temperature is higher than a predetermined value. Fan 40 also may be actuated manually and is so actuated whenever the oven is set to self-cleaning. Thus, fan 40 is energized to draw air upwardly through air jacket 36 as indicated by arrows whenever the oven temperature exceeds a predetermined value, or such fan is manually set into operation, the air being drawn from the ambient atmosphere through the spaces between cabinet 26 and the oven housing 12 along the sides and across the bottom of the front portions thereof. Thermostat 50 assures that such ventilating action will be automatically instituted and continued whenever the oven temperature reaches the point necessitating such ventilation.

The exhaust air, indicated by arrows 45, which is drawn from oven can 11 through filter 42 is mixed with the large volume of ambient cooling air indicated by arrows 60 and thus is rapidly reduced in temperature so that by the time it passes through fan 40 to exhaust piping 63 it is well below a temperature such as to permit the use of exhaust piping having a single wall. Air jacket 36, in view of the fact that it surrounds the oven at the rear, side and top portions thereof, provides a highly effective cooling jacket by virtue of the air flow induced therethrough by fan 40.

Control switch 65 is utilized to assure that the heaters used for self-cleaning operation will not be energized except when fan 40 is operating. As indicated in FIG. 5, control switch 65 is located between power source 55 and the oven heater control 67 and operates in response to flap member 70 which is hingedly mounted on the wall of oven housing 12. Flap member 70 is driven by the air stream indicated by arrows 60 when fan 40 is operating, and under such conditions closes control switch 65. In the absence of fan operation, the control switch is deactuated and energization of the heater necessary for self-cleaning operation is prevented.

The device of this invention thus provides highly effective means for ventilating and cooling an oven during its self-cleaning operation to prevent the overheating of the exposed portions thereof.

While the device of the invention has been described and illustrated in detail, it is to be clearly understood that this is intended by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of this invention being limited only by the 3 terms of the following claim.

We claim: 1. In combination, a self-cleaning oven, said oven having exhaust aperture means formed therein, a housing,

said oven being mounted in said housing; and

means for cooling and ventilating said oven, comprisexhaust piping connected to said housing, said exhaust piping extending from the top of said housing,

an air jacket being formed between said housing and said oven, said air jacket surrounding said oven on the side, bottom, top and back portions thereof,

air jacket intake means mounted on said oven housing in the vicinity of said exhaust aperture means for passing exhaust gasses from said aperture means to said air jacket, fan means mounted on said housing and interposed between said piping and said air jacket for drawing air into said jacket from the ambient atmosphere and exhaust gas and ambient air through said air jacket intake means and for driving said air and gas into said exhaust piping, an oven heater control controlling the self cleaning of said oven, a flap member interposed between said fan means and said piping, and control switch means for controlling the energization of said oven heater control, said flap means being adapted to actuate said control switch means only when said fan means is operatmg.

References Cited UNITED STATES PATENTS 2,839,044 6/1958 Phares 126-19 XR 2,868,108 1/1959 Petersen 98-115 3,032,028 5/1962 Pearce et al. 126--21 3,051,158 8/1962 Kimberly 1262l 3,066,212 11/1962 Hurko 126-273 XR 3,109,358 11/1963 Meyer 98115 3,150,655 9/1964 Saponara 12621 3,205,884 9/1965 Locher 126-273 XR 3,293,411 12/1966 Dills 126-19 XR ROBERT A. OLEARY, Primary Examiner.

M. A. ANTONAKAS, Assistant Examiner. 

